The present invention relates to novel acrylofunctional silicones, and to the method for making them.
Acrylofunctional silicones are useful, easily cured materials, finding use in such diverse areas as optical fiber cladding, paper coating, abrasion resistant coatings for plastics, and other uses. By acrylofunctional silicone it is meant herein a silicone having pendant groups that are conceptual, if not actual, derivatives of acrylic acid, e.g. silicones containing methacrylo groups, ethacrylo groups and the like.
Acrylofunctional silicones have been synthesized by various procedures. For example, they have been synthesized by reacting chloroalkyl substituted silicones with acrylic acid or methacrylic acid. The chloroalkyl substituted silicones themselves are made by special procedures.
Another method of synthesis of acrylofunctional silicones is disclosed in U.S. Pat. No. 4,359,369, issued Nov. 16, 1982 to Takamizawa et al. This patent describes the addition of an acrylo-acid chloride to a mercaptoalkyl substituted polydiorganosiloxane. In this reaction, it is necessary to provide an acid scavenger to eliminate byproduct HCl.
U.S. Pat. No. 4,293,397, issued to Sato et al. Oct. 6, 1981, discloses the addition of a glycidyl acrylate or a glycidyl methacrylate to an amino-terminated diorganopolysiloxane.
U.S. Pat. No. 4,369,300, issued Jan. 18, 1983 to Carter et al. discloses the reaction of a silicone carbinol, a polyisocyanate, and an hydroxyacrylate to produce an acrylofunctional silicone.
Application for U.S. Patent Ser. No. 683,308, entitled "Hydrophilic Silicone-Organic Copolymer Elastomers", applied for by Chi Long Lee, filed of even date with the present application, and assigned to the assignee of the present application, discloses the reaction of isocyanatoethylmethacrylate with polydimethylsiloxanepolyether copolymers.
None of these cited methods is more than superficially similar to the method of the present invention. Moreover, none of these cited methods results in the compositions of the present invention.